> > however i understand why some people do it the first way. after the "in"
> > you're in some sort of new scope (previous scope augmented by your
> > let binds)
>
> On the other hand, the 'let' scope will end exactly at the same place as
> the englobing scope. Since you can't close one without closing the
> other, 

That's not true. 

let x =
  let y =
    let z = ()
    in
      ()
  in
    () (* z no longer in scope *)
and a = ()
in
  (* y and z no longer in scope *)


> it doesn't make a lot of sense (both practically and mentally) to
> distinguish them, thru indentation of otherwise.

Depends on whether you like to initialise non-trivial values with separate
one-off functions or with nested lets. Personally, I prefer the latter but
that's a matter of style/taste, not sense.


David